Thanks for writing this. This sort of evaluation, which has the potential to radically change the consensus view on a charity, seems significantly under-supplied in our community, even though individual instances are tractable for a lone individual to produce. It’s also obviously good timing at the start of the giving season.
I think the post would be improved without the section on contraception, however. There are many simple environmental interventions we could benchmark against instead, that don’t involve population ethics. Preventing a future human from being born has many impacts—they will probably have a job, some probability of inventing a new discovery, and most importantly they will probably be grateful to be alive—of which emitting some CO2 is likely to be one of the smaller impacts. Any evaluation of contraception that only looks at direct environmental impact is going to be so lacking that I suspect you’d be better off choosing a different intervention to compare to.
Also, the cases for contraception and female education as climate-change interventions seem much, much more speculative than the case for rainforest conservation, so much so that their respective cost-effectiveness numbers probably ought not to be directly compared.
I agree on a meta level that the section on contraception shouldn’t be here.
On the object level, this isn’t the first time I’ve seen a charity analysis make the assumption that a problem can be completely solved if you multiply “cost to solve X% of the problem” by 100/X. This seems unlikely to be true in most cases, and is an important mistake to avoid.
For example, even if Guttmacher is correct that $9.4 billion will allow us to meet all unmet demand for contraceptives, contraceptives aren’t always used correctly, and even when used correctly, they don’t always work, so we won’t stop all 74 million unintended pregnancies. Also, not every unintended pregnancy leads to a child being born. And I suspect (from a brief skim of the report, I could be wrong here) that the $9.4 billion number involves some basic multiplication on Guttmacher’s part, without fully accounting for how difficult it is to reach different populations (in communities where contraceptives are forbidden, how much will it cost to change that policy?).
It’s still valuable to estimate and round, but the “multiply the number of people by the cost per person” fallacy (is there a catchier name?) seems like it routinely underestimates the cost of fully “fixing” a problem for reasons like these: Some % of your target population is hard to reach, and the thing that you think will always fix the problem only fixes it some % of the time.
Aaron, I think we agree that the contraception section is not the strongest part of the post. On your specific point though, I don’t think it’s actually so bad to use the $9.4bn divided by 74 million.
You suspect that $9.4bn is calculated by looking at data from a much smaller sample and performing a simple extrapolation. So do I. But that’s actually exactly what we want—this advice is intended for people donating thousands, not billions. (This point is what I was trying to get at with my note about more-expensive “last-mile” contraceptive needs).
Good points all. Yours was a reasonable estimate, but the topic made it a good way to discuss certain general problems with this type of estimate, which are often more prominent in estimates made by other people in other situations.
(Also, I didn’t spot the “last mile” comment; sorry for missing that, and thanks for calling it to my attention.)
Thanks for writing this. This sort of evaluation, which has the potential to radically change the consensus view on a charity, seems significantly under-supplied in our community, even though individual instances are tractable for a lone individual to produce. It’s also obviously good timing at the start of the giving season.
I think the post would be improved without the section on contraception, however. There are many simple environmental interventions we could benchmark against instead, that don’t involve population ethics. Preventing a future human from being born has many impacts—they will probably have a job, some probability of inventing a new discovery, and most importantly they will probably be grateful to be alive—of which emitting some CO2 is likely to be one of the smaller impacts. Any evaluation of contraception that only looks at direct environmental impact is going to be so lacking that I suspect you’d be better off choosing a different intervention to compare to.
Also, the cases for contraception and female education as climate-change interventions seem much, much more speculative than the case for rainforest conservation, so much so that their respective cost-effectiveness numbers probably ought not to be directly compared.
I agree on a meta level that the section on contraception shouldn’t be here.
On the object level, this isn’t the first time I’ve seen a charity analysis make the assumption that a problem can be completely solved if you multiply “cost to solve X% of the problem” by 100/X. This seems unlikely to be true in most cases, and is an important mistake to avoid.
For example, even if Guttmacher is correct that $9.4 billion will allow us to meet all unmet demand for contraceptives, contraceptives aren’t always used correctly, and even when used correctly, they don’t always work, so we won’t stop all 74 million unintended pregnancies. Also, not every unintended pregnancy leads to a child being born. And I suspect (from a brief skim of the report, I could be wrong here) that the $9.4 billion number involves some basic multiplication on Guttmacher’s part, without fully accounting for how difficult it is to reach different populations (in communities where contraceptives are forbidden, how much will it cost to change that policy?).
It’s still valuable to estimate and round, but the “multiply the number of people by the cost per person” fallacy (is there a catchier name?) seems like it routinely underestimates the cost of fully “fixing” a problem for reasons like these: Some % of your target population is hard to reach, and the thing that you think will always fix the problem only fixes it some % of the time.
Aaron, I think we agree that the contraception section is not the strongest part of the post. On your specific point though, I don’t think it’s actually so bad to use the $9.4bn divided by 74 million.
You suspect that $9.4bn is calculated by looking at data from a much smaller sample and performing a simple extrapolation. So do I. But that’s actually exactly what we want—this advice is intended for people donating thousands, not billions. (This point is what I was trying to get at with my note about more-expensive “last-mile” contraceptive needs).
Also remember I’m aiming for a rough estimate.
Good points all. Yours was a reasonable estimate, but the topic made it a good way to discuss certain general problems with this type of estimate, which are often more prominent in estimates made by other people in other situations.
(Also, I didn’t spot the “last mile” comment; sorry for missing that, and thanks for calling it to my attention.)
Thanks Larks and Taymon. Your comments about the section on contraception is probably fair.